Complementary and alternative medicines (CAM) are becoming increasingly popular among cancer patients as a means to counteract the toxic effects of chemotherapeutics. Non-conventional therapies like CAMs might provide additive or synergistic effects, but may also counteract the effectiveness of established medical treatments. In the proposed studies, we will use three mouse models for colorectal cancer (CRC), the ApcMin/+ model, the azoxymethane (AOM) model and the MC38 syngeneic transfer model, to examine the interaction between CAMs and EGFR inhibition, an emerging molecule-targeted treatment for colorectal and other cancers. The proposed studies will test the effect of commonly used biological-based CAMs, green tea and Vitamin D, on the effectiveness of EGFR-targeted treatment and evaluate whether interactions occur between the therapies. The CAMs were chosen based on scientific evidence for their potential roles in inhibiting colorectal carcinogenesis and their frequency of use. We hypothesize that combinations of currently acceptable medical treatments and CAMs will have unpredictable interactions that may significantly impact, either positively or negatively, the efficacy of standard treatments.